Abrasion resistant mechanical member with composite nickel-plating layer having meshlike porous portion and a method for manufacture thereof

ABSTRACT

An abrasion resistant mechanical member haivng a composite nickel plating layer on the surface of the member, which is formed by electrolysis by the use of a nickel electroplating bath. To achieve the intended purpose, the nickel electroplating bath is added with tensile stress accelerating agent and compression stress accelerating agent in addition to ceramic powder. The electrodeposited member is subsequently subjected to reverse electrolysis for forming a porous portion in the composite nickel electroplating layer which exhibits an excellent oil retention together with abrasion resistance.

United States Patent Shigeta et a1.

ABRASION RESISTANT MECHANICAL MEMBER WITH COMPOSITE NICKEL-PLATING LAYER HAVING MESHLIKE POROUS PORTION AND A METHOD FOR MANUFACTURE THEREOF Inventors: Toshihiko Shigeta, Kure; Toshio Yamada, Aki; Takao Sasame, Hiroshima; Yoshitaka Uehayashi, Aki, all of Japan Assignee: Toyo Kogyo Co., Ltd., Hiroshima,

Japan Filed: June 1, 1973 Appl. No.: 366,019

Foreign Application Priority Data June 3, 1972 Japan 47-55257 US. Cl. 204/16; 29/1912, 29/195; 204/23; 204/35 R; 204/49; 204/l29.95

Int. Cl....,. C23b 7/00; C23b 5/00; C23b 5/08 Field 01' Search 204/16, 35 R, 23, 38 R, 204/38 C, 49, 181, 129.55; 29/1912, 195

References Cited UNITED STATES PATENTS 3/1943 Van der Horst 204/26 1 June 17, 1975 2,412,698 12/1946 Van der Horst 204/26 3,061,525 10/1962 Grazen 204/16 3,438,789 4/1969 Weiss et al 204/23 3,514,389 5/1970 Stephan et al. 204/237 3,582,481 6/1971 Hovey 204/16 3,640,799 2/1972 Stephan et a1. 204/16 OTHER PUBLICATIONS Modern Electroplating, Edited by Fred Lowenheim, 2nd Edition, 1963, pgs. 269-271, 282-286, 307.

Primary Examiner-T. M. Tufariello Attorney, Agent, or FirmWenderoth, Lind & Ponack [57} ABSTRACT An abrasion resistant mechanical member haivng a composite nickel plating layer on the surface of the member, which is formed by electrolysis by the use of a nickel electroplating bath. To achieve the intended purpose, the nickel electroplating bath is added with tensile stress accelerating agent and compression stress accelerating agent in addition to ceramic powder. The electrodeposited member is subsequently subjected to reverse electrolysis for forming a porous portion in the composite nickel electroplating layer which exhibits an excellent oil retention together with abrasion resistance.

6 Claims, 4 Drawing Figures PATENTEUJUH 1 T I915 3.890.209

SHEET 1 FlG.l

FIG.2

PATENTEDJUN i 7 ms 3x55? 2 F/G.3 seizing Test l2 g i l0 i- 0 2 E i F Conventional Invention F/Gi4 Abrasion Test Amount of Abrasion W4 Conventional Invention 1 ABRASION RESISTANT MECHANICAL MEMBER WITH COMPOSITE NICKEL-PLATING LAYER HAVING MESHLIKE POROUS PORTION AND A METHOD FOR MANUFACTURE THEREOF The present invention relates to an abrasionresistant member or article with a nickel plating layer having superior abrasion resistance and lubrication and, more particularly, to an abrasion-resistant member or article I with composite nickel plating layers which contain ceramic powders of metallic carbide, oxide, nitride, etc. as abrasion-resistant elements and is provided with mesh-like porous portion for the retention of lubricating oil. The present invention also relates to a method for forming the composite nickel plating layer (i.e., nickel plating layer containing ceramic powders) with the meshlike porous portion.

As a method of obtaining abrasion-resistant mechanical members, there is known a composite nickel plating which is provided with abrasion resistance by mixing the ceramic powders of silicon carbide (SiC), etc. in a nickel plating bath whereby the ceramic powders may be contained in the nickel plating layer which is electrodeposited on the mechanical member, as disclosed in, for example, the US. Pat. No. 3,514,389. However, although such conventonal composite nickel plating layers are superior in abrasion resistance, they are inferior in oil retention and lubrication.

It is an essential object of the present invention to provide better lubricating oil retention to a composite nickel plating layer with conventional abrasion resistance.

According to the present invention, there is provided an abrasion-resistant mechanical member with a composite nickel plating layer containing ceramic powder therein and having mesh-like porous portion, wherein preferably numerous grooves of approximately 0.01 to 0.5 mm in width are arranged like meshes at intervals of approximately 0.5 to 9 mm.

Furthermore. according to the present invention, there is also provided a method for forming the composite nickel plating layer, wherein a tensile stress accelerating agent in an amount of 0.05 to 5.g/lit. and compression stress accelerating agent in an amount of 0.l to 10 g/lit. are added to a nickel plating bath containing 50 to 500 g/lit. of ceramic powders, thereby to perform electroplating, a non-peeling composite nickel plating with cracks caused by tensile stress being formed on the member and, subsequently, reverse electrolysis being performed in a reverse electrolysis bath through stirring operation, numerous grooves of approximately 0.0l to 0.5 mm in width in a meshlike formation at intervals of approximately 0.5 to 9 mm.

The other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the drawings, in which;

FIG. 1 is a photomicrograph, times, showing the surface of a composite nickel plating layer with meshlike porous portion of the present invention,

FIG. 2 is a photomicrograph, ll5 times, showing a partially enlarged section of FIG. 1.

FIG. 3 is a graph showing the time required up to seizing, respectively, of the present invention and the conventional one in a seizing test, and

FIG. 4 is a graph showing abrasion amount, respectively, of the present invention and the conventional one in an abrasion test.

In the present inventioin, any of ordinary watt type bath, chloride bath and sulfamine acid bath may be used as a nickel plating bath.

For ceramic powders to be added as abrasion resistant material, metallic oxide such as aluminum oxide, etc., metallic carbide such as silicon carbide, titanium O carbide, etc., metallic nitride such as boron nitride, ti-

tanium nitride, etc., or a mixture thereof may be used. The ceramics of 0.5 to 9 p. in particle size are preferably used. The amount of ceramics to be added is required to be 50 to 500 g/lit. with respect to the nickel plating bath. Namely, the abrasion resistant plating layer cannot be obtained if the amount of ceramic powder added is 50 g/lit. or less, while, if it is 500 g/lit. or more, the abrasion resistance of the plating layer does not improve propositionately, but the plating conditions become worse.

Furthermore, in the present invention, the tensile stress accelerating agent and compression stress accel erating agent for the plating layer are added to the plating bath in the range of 0.05 to 5 g/lit, and 0.1 to 10 g./lit., respectively, with respect to the plating bath. Proportions may vary in these ranges in consideration of the amount of ceramic powders and the type of plating bath.

Generally, in nickel plating, cracks are not produced easily in the plating layer because of the properties of the nickel plating. Furthermore, in the composite nickel plating containing ceramic powders, the ceramic powders act to relieve concentration of the tensile stress that produces in the plating layer and, accordingly, cracks are further prevented from being produced on the composite nickel plating layer. However, according to the present invention, tensile pressure is concentrated on the plating layer by electrodepositing by adding a tensile stress accelerating agent in an amount sufficient to overcome the effect of the compression pressure accelerating agent which is added for avoiding peeling of the plating layer, whereby the mesh-like cracks may be formed. The amount of the tensile stress accelerating agent added is 0.05 to 5 g/lit., since the tensile stress becomes smaller for addition of 0.05 g/lit. or less and no cracks are produced on the plating layer, while the internal stress thereof becomes great for addition of 5 g/lit. or more, thus causing the cracks and the peeling of the plating layer simultaneously. Also, the compression stress accelerating agent is required to rigidly electrodeposite the nickel plating layer without the latter peeled off from the member. However, 0.l to 10 g/lit. is selected as the amount of the compression stress accelerating agent to be added, since, if it is 0.l g/lit. or less, the balancing effect between the compression stress accelerating agent and the tensile stress accelerating agent disappears. Thus, the plating layer is influenced by only the tensile stress accelerating agent, and peeling is caused. Also, if the addition amount is 10 g/lit. or more, cracking caused by the tensile stress accelerating agent is controlled excessively. Accordingly, a larger amount of tensile stress accelerating agent is required, thus making the plating condition of the nickel plating bath itself worse.

As described hereinbefore, various plating baths can be used and, particularly, a chloride bath is best since the tensile stress caused on the electroplated layer becomes naturally greater as compared with other plating baths. Accordingly, in using the chloride bath, the amount of the tensile stress accelerating agent to be added may be comparatively less. Therefore, the amount of the compression stress accelerating agent to be added can also be less. Namely, in using the chloride bath as a nickel plating bath, the amounts of both the tensile stress accelerating agent and the compression stress accelerating agent to be added may be. respcc tively. 0.05 to g/lit. and 0.] to 5 g/lit.

ln embodying the present invention. butyne-ldioll,4 is best as the tensile stress accelerating agent and sacharin combination is best as the compression stress accelerating agent. Using the above mentioned plating bath, electroplating is performed at bath temperature of 40 to 75C.. current density of 2 to 50 A/dm and pH value of 3.5 to 5.3. These conditions are quite the same as for ordinary composite plating. By performing electrodcposition under the above mentioned conditions, a composite nickel plating layer, with mesh-like and fine cracks. including the ceramic powders are produced on the member treated.

Subsequently. by subjecting it in the reverse electrolysis, preferably, through stirring operation thereby to enlarge the fine cracks. the composite plating layer, wherein numerous grooves of approximately 0.01 to 0.5 mm in width are arranged like meshes at intervals of approximately 0.5 to 9 mm, is obtained.

For reverse electrolysis. either inorganic acid bath or organic acid bath may be used. The chromium acid bath has been proved to be optimum although the reason therefor is not unknown. The concentration of the reverse electrolysis bath is the same as that of the reverse electrolysis in ordinary plating, for example, chromium plating. and a range of approximately I to 50% may be applied. Also. the temperature, current density and reverse electrolysis period in the reverse electrolysis bath may be selected properly by the desired width of each groove of the resultant composite nickel plating layer.

Furthermore. 0.0] to 0.5 mm is selected for the groove width of each groove of the mesh-like porous portion on the composite nickel plating layer, since, if it is 0.01 mm or less, the lubricating oil retention can not be expected. while. if it is 0.5 mm or more, the porous portion is increased. thus reducing the abrasion resistance of the composite nickel plating layer. Also. 05 to 9 mm is selected for the intervals amoung grooves, since. if it is 0.5 mm or less, the mesh-like porous portion is excessively finely divided, thus reducing the strength of the plating layer itself, while, if it is 9 mm or more. the ratio of the porous portion with respect to the entire plating layer becomes smaller, thus reducing the lubricating oil retention.

One preferred embodiment of the present invention will be hereinafter described by way of example.

EXAMPLE I Compositions of Nickel Electrolysis:

Temperature -Continued EXAMPLE I pH Value 4.9 Current Density 20 A/dm Electrodepositing Time 2 hours (with air stirring operation) Compositions of Reverse Electrolysis (Chromium acid bath):

CrO; lie chromium trioxidel 250 g/lit, H- ,SO 2.5 g/lit. Na- ,SiF., (i.e.. soda silicol g/lit. fluoride) Reverse Electrol sis Conditions:

Temperature 40C, Current Density 20 A/dm Reverse Electrodepositing Time It] minutes Under the above mentioned conditions, a platig layer with mesh-like porous portion as shown in FIGS. 1 and 2 is obtained.

Subsequently, a seizing test and an abrasion test for the composite plating layer produced as shown above will be hereinafter described.

l. Seizing Test An internal contact type drum tester is used, which is designed to test the seizing and abrasion conditions of the internal peripheral face of specimens and rotary member by rotating a rotary member of a given shape while pushing it against the internal peripheral face of cylindrically formed specimen.

Testing Conditions:

Load in installation l.5 kg Sliding Velocity 25 m/sec. Eccentric amount 0 The rotary member employed is made of special cast iron which is 60 mm in length, 8.5 mm in height and 6 mm in width. sliding contact being formed on a curved face of 4 mm in radius. The drum specimen is mm in inner diameter and the inner peripheral face of which is nickel-plated in accordance with the present invention. This drum specimen is dipped in engine oil for a given period of time after having been heated to a given temperature and thereafter the oil attached on the surface thereof is wiped out.

The results thereof show lubrication performance which is twice or four times as better as that of the conventional one with no porous portion, as shown in FIG. 3. 2. Abrasion Test:

The internal contact type drum tester is used.

Testing Conditions:

The rotary member and drum specimen employed are the same as employed in the seizing Test.

50 hours 20 to 30 cc/hr.

Testing Time Lubricant l0W-30) The results thereof show remarkably reduced abrasion and superior abrasion resistance as compared with those of the conventional one with no porous portion, as shown in FIG. 4.

Although the present invention has been fully described by way of example with reference to the ac companying drawings showing the preferred embodiment thereof, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are. unless otherwise departing from the scope of the present invention, to be understood as included therein since the present invention is not to be limited by the above preferred embodiment thereof.

What is claimed is:

1. An abrasion-resistant mechanical member which comprises a composite nickel-electroplated layer on the surface of said member, said layer having a meshlike porous portion which contains therein ceramic powder as an abrasion resistant element, said porous portion being composed of grooves of approximately 0.01 to 05 mm in width and present at intervals of approximately ().5 to 9 mm. thereby to provide an oil retention characteristic.

2. A method for manufacturing an abrasion-resistant mechanical member having a composite nickelelectroplated layer on the surface of said member, said layer having a mesh-like porous portion which contains therein ceramic powder as an abrasion resistant ele ment and is composed of grooves of approximately ().()I to 0.5 mm. in width and present at intervals of approximately ().5 to 9 mm. thereby to provide an oil retention characteristic, which comprises a step of electrodepositing a workpiece in a nickel-plating bath containing therein a ceramic powder in an amount of 50 to 500 g/lit., said bath further containing a tensile stress accelerating agent in an amount of 0.05 to 5 g/lit. with respect to the total volume of said bath and a compression stress accelerating agent in an amount of 0.1 to ID g/lit. with respect to the total volume of said bath, the amount of said compression stress accelerating agent being sufficient to permit the action of said tensile stress accelerating agent to overcome the action of said compression stress accelerating agent, thereby to form the nickel-electroplated layer having fine cracks developing in a mesh-like manner and caused by the presence of said tensile stress accelerating agent, and a step of subjecting the resultant member to reverse electrolysis thereby to impart the particular grooves of the particular size to said composite nickel-electroplated layer.

3. A method as claimed in claim 2, wherein said tensile stress accelerating agent is butyne-2-diol-L4 and said compression stress accelerating agent is saccharin.

4. A method as claimed in claim 3, wherein the re verse electrolysis is carried by the use of a chromium acid bath of 1 to 50% S. A method as claimed in claim 2, wherein said nickel electroplating bath comprises a chloride bath and wherein the amount of said tensile stress accelerating agent is within the range of 0.05 to 2 g/lit, and the amount of said compression stress accelerating agent is within the range of 0.1 to 5 g/lit.

6. A method as claimed in claim 4 wherein the elec trodepositing is carried out at a bath temperature of40 to 75C. a current density of 2 to 50 A/dni and a pH value of 3.5 to 5.3. 

1. AN ABRASION-RESISTANT MECHANICAL MEMBER WHICH COMPRISES A COMPOSITE NICKEL-ELECTROPLATED LAYER ON THE SURFACE OF SAID MEMBER, SAID LAYER HAVING A MESH-LIKE POROUS PORTION WHICH CONTAINS THEREIN CERAMIC POWDER AS AN ABRASION RESISTANT ELEMENT, SAID POROUS PORTION BEING COMPOSED OF GROOVES OF APPROXIMATELY 0.01 TO 0.5 MM IN WIDTH AND PERCENT AT
 2. A method for manufacturing an abrasion-resistant mechanical member having a composite nickel-electroplated layer on the surface of said member, said layer having a mesh-like porous portion which contains therein ceramic powder as an abrasion resistant element and is cOmposed of grooves of approximately 0.01 to 0.5 mm. in width and present at intervals of approximately 0.5 to 9 mm. thereby to provide an oil retention characteristic, which comprises a step of electrodepositing a workpiece in a nickel-plating bath containing therein a ceramic powder in an amount of 50 to 500 g/lit., said bath further containing a tensile stress accelerating agent in an amount of 0.05 to 5 g/lit. with respect to the total volume of said bath and a compression stress accelerating agent in an amount of 0.1 to 10 g/lit. with respect to the total volume of said bath, the amount of said compression stress accelerating agent being sufficient to permit the action of said tensile stress accelerating agent to overcome the action of said compression stress accelerating agent, thereby to form the nickel-electroplated layer having fine cracks developing in a mesh-like manner and caused by the presence of said tensile stress accelerating agent, and a step of subjecting the resultant member to reverse electrolysis thereby to impart the particular grooves of the particular size to said composite nickel-electroplated layer.
 3. A method as claimed in claim 2, wherein said tensile stress accelerating agent is butyne-2-diol-1,4 and said compression stress accelerating agent is saccharin.
 4. A method as claimed in claim 3, wherein the reverse electrolysis is carried by the use of a chromium acid bath of 1 to 50%.
 5. A method as claimed in claim 2, wherein said nickel electroplating bath comprises a chloride bath and wherein the amount of said tensile stress accelerating agent is within the range of 0.05 to 2 g/lit. and the amount of said compression stress accelerating agent is within the range of 0.1 to 5 g/lit.
 6. A method as claimed in claim 4 wherein the electrodepositing is carried out at a bath temperature of 40* to 75*C, a current density of 2 to 50 A/dm2 and a pH value of 3.5 to 5.3. 